Over the next several years, the aeronautical communication infrastructure will evolve as a result of two major ongoing Air Traffic Management (ATM) modernization programs. These include the Single European Sky ATM Research (SESAR) program in Europe and the Next Generation Air Transportation System (NextGen) in the United States. Despite their differences, both of these programs assume that future ATM will diverge from voice communication and will heavily rely on air/air and air/ground data exchanges.
Already before SESAR and NextGen, the joint Eurocontrol and Federal Aviation Administration (FAA) program “Action Plan 17” (AP17) identified a possible need for up to three new communication technologies primarily supporting Air Traffic Control (ATC) and Airline Operational Center (AOC) services. These new communication technologies include the airport local communication system such as the Aeronautical Mobile Aircraft Communication System (AeroMACS), new terrestrial line-of-sight communication systems such as the L-band Digital Aeronautical Communication System (L-DACS), and a new satellite communication (SatCom) system. Only AeroMACS is currently being pursued by both Europe and the U.S. The L-DACS and new SatCom system are being developed in Europe within the SESAR program and the European Space Agency (ESA) program Iris. On the contrary, the FAA and NextGen currently rely on upgrades of the existing very high frequency (VHF) datalink technologies. This implies that if the European programs are successful and the U.S. maintains the current approach based on legacy systems, future aircraft flying from SESAR to NextGen airspace will need to be equipped with a set of communication avionics compliant with two different sets of requirements.
Furthermore, even if the SESAR solution is adopted in other parts of the world and aligned with NextGen, there will always be many regions where the required modernization of the ATM infrastructure will not be affordable and where only the legacy voice communication system will be used for many years. As such, most likely there will be a very long transition period, when many exemptions may be provided to existing aircraft equipped with legacy avionics.
A promising technology for this future environment is the flexible avionics radio architecture based on distributed Software Defined Radio (SDR) principles. While many of the state-of-the-art radios employ SDR technology, there is still a need for concrete solutions related to the interconnection fabric employed in SDR systems to provide the flexibility and redundancy needed for aircraft communication systems.